No description available.

Thesis (M. D. S.)--University of Hong Kong, 2009. / Includes bibliographical references (leaves 48-67). Also available in print.

Thesis (Ph. D.)--Oregon State University, 2010. / Printout. Includes bibliographical references. Also available on the World Wide Web.

Thesis (M. Phil.)--University of Hong Kong, 1988.

The research described here explores the ability of dual H-bond donor catalysts to induce asymmetry in a variety of synthetically useful transformations that proceed via diverse reactive intermediates. In Chapters 1-3, we investigate ureas and thioureas as anion-binding catalysts for asymmetric reactions that proceeed via cationic intermediates with little precedent as electrophiles in asymmetric catalysis. Chapter 4 details our application of H-bond donor catalysis to the Cope-type hydroamination. Chapter 1 describes the development of an asymmetric aldehyde alkylation catalyzed by a bifunctional primary aminothiourea. A variety of 2-aryl propionaldehydes are alkylated with benzhydryl bromides in moderate to good yields and good enantioselectivities. Catalyst structure-activity relationship studies of the alkylation pointed towards electrophile activation by the dual H-bond donor moiety. Experiments aimed at gaining a better understanding of the electophile activation mode and characterizing the activated electrophilic intermediate in the alkylation reaction are described in Chapter 2. The development of an enantioselective cyanide addition to N,N-dialkyliminium intermediates is the subject of Chapter 3. A variety of strategies for accessing N,N- dialkyliminium ions are established, and chiral thioureas are shown to promote the addition of cyanide to such intermediates with moderate enantioselectivities. Chapter 4 details our discovery that thioureas bearing polarizable and conformationally constrained aromatic groups catalyze highly enantioselective Cope-type hydroaminations. This powerful transformation provides a variety of chiral pyrrolidine products under mild reaction conditions. / Chemistry and Chemical Biology

The purpose of this multiple case study was to examine the experiences of adolescent students and their adult relatives participating in The Family Orchestra Project, a program designed to promote family bonding through shared musical study and performance. Participants of this study were four adult-child dyads. Data collected included field notes, a questionnaire, a focus group interview, adult-child pair interviews, audio recordings, written prompts, and a video recording. Five cross-case themes emerged during coding and data analysis: Role Reversal, Patience, Practice, Bonding, and Group Music Making. The findings of the study reveal that a shared music making experience such as The Family Orchestra Project can facilitate adult-child bonding and communication during early adolescence while also challenging the individuals to grow as they assume nontraditional roles in their relationship. Implications for practice in the music education of adolescents are discussed and recommendations for future research are provided in the concluding chapter.

No description available.

Structure and bonding properties of gold (Au) nanoparticles (NPs) are of great interest due to the unique size-dependent quantum-confinement effect exhibited by structures on the nanoscale. As such, Au NPs have demonstrated their potential use in a variety of fields (e.g. imaging, drug delivery, catalysis). The popularity of Au NPs is largely due to its versatility in synthesizing different NP compositions and surfaces. In this thesis, structure and bonding in Au NPs was examined from both surface functionalization/ligand and composition/metal bonding perspectives. Functionalization of Au-surface with model biomolecule ligands enables formation and electroless deposition of Au NPs onto a biocompatible Ti substrate. Through variation of model biomolecule size and concentration with respect to a Au precursor, insight was gained into the formation mechanisms of Au NPs, and the processes that lead to deposition upon the Ti substrate. Furthermore, using extended X-ray absorption fine-structure (EXAFS) with sample spinning and glancing angle setup allowed us to resolve small differences in coordination, leading to new findings on fine-tuning of peptide-coated Au NP size on Ti substrates. To explicitly analyze Au NP structure and bonding from a metallic perspective, NP model systems with precisely controlled compositions were studied with ab initio calculations to compare local environment and electronic character. It was determined that while surface features may be structurally similar, the effect of local environment and geometry can affect the electronic character of these features. Finally, small Au NP samples were studied to understand the alloying effect. The position of a heteroatom dopant Pt atom within Au25 has been a disputed issue, with no definitive means of determination. Using a combination of EXAFS spectra and ab initio calculations, it was possible to determine that the Pt atom resides in the central position of the icosahedral core. Furthermore, Pt doping in Au25 resulted in a contraction of the surface Au structure, an unobserved phenomenon until now. Through the careful and systematic comparison of Au NP systems, this thesis will contribute to a better understanding of Au local structure and bonding in ligand-functionalized substrate-supported Au NPs, as well as compositionally precise Au nanoclusters.

No description available.

A series of experiments were conducted to explore the hydration state of the mineral lausenite. The experiments of Posnjak and Merwin (1922) were recreated and the conclusion is reached that lausenite is of mineral formula Fe2(SO4)3∙5H2O, rather than Fe2(SO4)3∙6H2O as suggested by Posnjak and Merwin (1922). This conclusion is based on the X-ray diffraction data which found that the Posnjak and Merwin experiments produced a phase whose pattern matched that of the pentahydrate identified by Majzlan (2005). The refractive index data and morphology of this phase is also a match for the mineral described previously as a hexahydrate by Posnjak and Merwin (1922) and Lausen (1928). Synchrotron X-ray diffraction data was collected from a possible new phase in the hydrous ferric sulfate system. The data were analyzed and a unit cell was identified with monoclinic unit cell dimensions of a = 7.532(3)Å b = 12.551(6)Å c = 7.077(4)Å and β = 96.775(8)° with a unit cell volume of 664.4Å3. This phase was determined to grow only at temperatures above 85°C and at a RH of ~23%. The atomic structures of the minerals quenstedtite [Fe2(SO4)3∙11H2O] and romerite [Fe2+Fe3+2(SO4)4∙14H2O] are refined, hydrogen positions are identified and hydrogen bonding scheme is discussed. The weakest hydrogen bonds are found to occur between layers of differently coordinated tetrahedral groups in both romerite and quenstedtite. The transition from romerite to quenstedtite involves the oxidation of the ferrous iron in romerite converting into a Fe3+(SO4)∙5H2O cluster. / Thesis (Master, Geological Sciences & Geological Engineering) -- Queen's University, 2012-09-02 10:11:21.232